WO2006129888A1

WO2006129888A1 - Hydraulic fluid composition for buffer

Info

Publication number: WO2006129888A1
Application number: PCT/JP2006/311679
Authority: WO
Inventors: Shinichi Shirahama; Toru Aoki; Naozumi Arimoto
Original assignee: Nippon Oil Corporation
Priority date: 2005-06-03
Filing date: 2006-06-05
Publication date: 2006-12-07

Abstract

A hydraulic fluid composition for buffers which enables a buffer comprising a piston, in particular, one having a sliding fluororesin material attached thereto, and a cylinder to have a piston/cylinder frictional force controlled according to the intended use of the buffer and which can retain the frictional properties for long. The hydraulic fluid composition for buffers is characterized by comprising a lube base oil and, incorporated therein, (A) at least one member selected among phosphoric esters and phosphorous esters each having a C3-30 hydrocarbon group and salts of the esters and (B) C6-30 (un)saturated fatty acid/glycerol esters which have a triester content of 10 mass% or lower based on the whole esters and in which the ratio by mass of the monoester to the sum of the monoester and the diester is 0.5 or higher.

Description

Description Hydraulic fluid composition for shock absorbers

[Technical field]

The present invention relates to a hydraulic fluid composition for a shock absorber, and more specifically, shows an initial friction characteristic between piston and cylinder in a shock absorber, in particular, between a piston and a cylinder fitted with a fluororesin sliding material. The present invention relates to a hydraulic fluid composition for a shock absorber that can be maintained for a long time.

[Background]

There are various types of shock absorbers, but they basically consist of a piston with a valve and a cylinder (also called an outer cylinder or tube). The piston is fixed to the rod. The piston slides on the cylinder inner surface, and the rod slides on the seal of the rod guide. The shock absorber is filled with hydraulic oil and, if necessary, gas and buffered by the resistance of the hydraulic oil passing through the valve. Nitrile rubber or fluorine-based rubber is used as the sealing material for the shock absorber mouth and mouth guide, and a sliding material called a piston band is attached to the piston. As this piston band, the above-mentioned sealing material is a highly durable fluororesin-based material, and in particular, a solid lubricant having self-lubricating property, for example, a graph, for further imparting low friction and durability. The use of grease materials including carbon materials such as eyes is being studied.

In the past, hydraulic fluids for shock absorbers have been used to reduce the seal friction coefficient of the hydraulic fluid in order to prevent stick-slip between the shock absorber seal and the rod and to ensure the durability of the seal. In order to reduce this coefficient of friction, additives such as phosphate esters and aliphatic amine compounds that reduce friction are generally blended with hydraulic oil (see, for example, Patent Documents 1 to 5). . Also, in recent years, as a result of research on reducing vibrations of automobiles and improving ride comfort and handling stability, the frictional force between piston head seals has been increased, and at the same time, piston rod / bush and piston There has been proposed a new hydraulic fluid composition for shock absorbers containing a specific amine compound or the like having a function of reducing the frictional force of the band Z cylinder (see, for example, Patent Document 6).

In any case, however, these friction characteristics are limited as long as the shock absorber is used. If it is not maintained, the designed riding comfort cannot be maintained. Also, since the purpose of the shock absorber varies depending on the type of sliding member, a hydraulic fluid for the shock absorber that shows the optimum friction characteristic depending on the type of sliding member is required. There is no examination.

Patent Document 1: Japanese Patent Laid-Open No. 5-2 5 5 6 8 3

Patent Document 2: Japanese Patent Laid-Open No. 7-2 2 4 2 9 3

Patent Document 3: Japanese Patent Laid-Open No. 7-2 5 8 6 7 8

Patent Document 4: Kaihei 6— 1 2 8 5 8 1

Patent Document 5: Japanese Patent Laid-Open No. 2 00 0-1 9 2 0 6 7

Patent Document 6: Japanese Patent Application Laid-Open No. 2000-0 1-9 4 3 7 6

[Disclosure of the Invention]

An object of the present invention is to provide a hydraulic fluid for a shock absorber capable of maintaining the friction characteristics designed to meet the purpose of the shock absorber as described above until the life of the shock absorber. In particular, it is to provide a hydraulic fluid for a shock absorber that can maintain a friction characteristic between a cylinder and a cylinder fitted with a fluororesin-based sliding material for a long period of time.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a specific phosphorus compound, a specific ester compound, and a specific basic nitrogen-containing compound are contained, in particular, a fluororesin. The present invention has been completed by finding a composition capable of maintaining the frictional characteristics between a piston band fitted with a sliding material and a cylinder for a long period of time. That is, the present invention provides a lubricating base oil comprising: (A) at least one selected from a phosphate ester having a hydrocarbon group having 3 to 30 carbon atoms, a phosphite ester, and a salt thereof; and (B) A glycerin ester of a saturated or unsaturated fatty acid having 6 to 30 carbon atoms, based on the total amount of the ester, 10% by mass or less of the ester, and the mass ratio of the monoester to the total monoester and diester A hydraulic fluid composition for shock absorbers, which comprises an ester having an N of 0.5 or more.

In the present invention, the component (A) is at least one selected from (A 1) a phosphate ester having a hydrocarbon group having 3 to 10 carbon atoms, a phosphite ester, and a salt thereof. In the hydraulic fluid composition for a shock absorber described above, In the present invention, the component (A) has (A 2) a (phosphite) ester having an alkyl group or an alkenyl group having 11 to 30 carbon atoms, the alkyl group or an alkenyl group ( Sub-) The hydraulic fluid composition for shock absorbers according to item 1, characterized in that it is at least one selected from phosphate esteramine salts.

Further, the present invention is the above-described hydraulic fluid composition for a shock absorber, further comprising (C) a basic nitrogen-containing compound.

Still another aspect of the present invention is the above-described hydraulic fluid composition for a shock absorber, which is for a shock absorber having a piston equipped with a fluororesin-based sliding material.

According to the present invention, by controlling the frictional force between the piston and the cylinder in the shock absorber, in particular, between the piston and the cylinder fitted with the piston band made of a fluororesin-based sliding material, This reduces the vibration of the vehicle and improves ride comfort and handling stability. In particular, when the frictional force is high, the damping force at the neutral position of the shock absorber is increased, and the vehicle body (spring (Upload) can be suppressed, and driver and passenger discomfort can be reduced. By using the hydraulic fluid composition for a shock absorber according to the present invention, the initial friction between the piston and the cylinder, in particular, between the piston and the cylinder fitted with the piston band made of a fluororesin-based sliding material. The characteristics can be maintained stably for a long period of time, and stable ride comfort and handling stability can be maintained throughout the life of the shock absorber. Hereinafter, the present invention will be described in detail.

The hydraulic fluid composition for a shock absorber according to the present invention is a composition suitable for controlling the frictional force between the cylinder and the cylinder to a required level according to the purpose of the shock absorber and maintaining the friction characteristics over a long period of time. It is.

There are no particular restrictions on the piston, but it is preferable that the piston is provided with a piston band, and the piston band is preferably a fluororesin-based material. The resin material is particularly preferably a fluororesin composite material containing a solid lubricant.

The fluororesin-based composite material containing a solid lubricant is not particularly limited as long as it is a fluororesin-based composite material containing a fluororesin and a solid lubricant.

Fluorine-based resin is not particularly limited as long as it contains fluorine, for example For example, polytetrafluoroethylene, polyvinylidene fluoride, polyhexafluoropropylene, polychlorotrif / reo-ethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene monohexaful Examples thereof include chloropropylene copolymers, tetrafluoroethylene monoperfluoroalkyl vinyl ether copolymers and the like. Among these, polytetrafluoroethylene and polytetrafluoroethylene are preferred, and polytetrafluoroethylene is preferred. Ethylene is particularly preferred. If necessary, other ingredients such as polyimide resin, polyamide resin, polyamide resin, silane-modified polyamide resin, epoxy resin, phenolic resin, and polyphenylene sulfide are also available. It may contain various resin materials such as glass, glass fiber, amide fiber, plasticizer, etc., and may contain the above-mentioned resins containing iodine, bromine, chlorine and the like.

Solid lubricants include molybdenum disulfide, tungsten disulfide, alumina, silica, iron oxide, chromium dioxide, boron nitride, silicon carbide, zinc sulfide, silver sulfide, copper sulfide, lead, tin, tantalum, Solid lubricants such as bismuth, natural graphite, synthetic graphite, various carbon blacks, and carbon fibers are listed. Among these, carbon-based lubricants such as molybdenum disulfide and graphite are preferred, and graphite is preferred. Especially preferred.

In the present invention, the composition ratio of the composite material is not particularly limited, fluororesin, preferably 5 0-9 9.9 mass ^_0/0, more preferably 6 0-9 9 wt%, preferably to more Is 70 to 95% by mass, and the solid lubricant is preferably 0.1 to 50% by mass, more preferably 1 to 40% by mass. The fluorine-containing resin composite material containing these solid lubricants is particularly preferably 5 to 30% by mass. The fluorine-based resin and the solid lubricant as described above, and other if necessary These components are dispersed and molded by a known method. For example, in a state where a fluororesin (which may contain other resins) is melted, or in the form of powder or fine particles The solid lubricant and various resins are mixed and dispersed uniformly, or the solid lubricant is dispersed on the surface of the fluororesin and molded into a desired shape. The fluororesin-based composite material containing these solid lubricants is used by being pressure-bonded to a sliding portion with a piston cylinder. In this case, the thickness is usually from 0.1 to 5 mm, preferably from 0.1 to 2 mm, particularly preferably from 0.2 to I m rn. In addition, the cylinder materials include steel materials, aluminum materials, magnesium materials, titanium materials, copper materials, lead materials, etc., or metal materials composed of these various alloys, or chromium nitride. Metal with hard thin film coating, such as titanium nitride, diamond, diamond diamond, diamond-like carbon (may be made of carbon alone, may contain metal, silicon, hydrogen, etc.) Various materials such as carbon-based materials such as carbon-based materials, graphite and carbon fiber, and resin-based materials listed above can be used, and there is no particular limitation. Among these, it is preferable to use the various metal materials listed above as the cylinder material. The lubricating base oil in the hydraulic fluid composition for shock absorbers of the present invention is not particularly limited, and mineral base oils and synthetic base oils used for ordinary lubricating oils can be used.

Specifically, mineral oil base oils can be obtained by removing the solvent oil fraction obtained by depressurizing and distilling atmospheric residual oil obtained by atmospheric distillation of crude oil, solvent extraction, hydrogen Base oil produced by isomerization of one or more treatments such as hydrocracking, solvent dewaxing, hydrorefining, etc., or wax isomerized mineral oil, GTLWAX (gastric liquid wax) Etc. can be illustrated.

Specific examples of synthetic base oils include polybutene or a hydride thereof; 1_octenoligomer, 1-decenoligoma 1 or other poly α-olefin or a hydride thereof; ditridecyl glutarate, Diesterol such as di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-hexylhexyl sebacate, etc .; Examples thereof include: Polyesters such as neat, pentaerythritol 1-ethylhexanoate and pentaerythritol pelargonate; aromatic synthetic oils such as alkylnaphthalene, alkylbenzene and aromatic ester; and mixtures thereof.

As the lubricating base oil in the present invention, the mineral base oil, the synthetic base oil, or an arbitrary mixture of two or more selected from these can be used. Examples thereof include one or more mineral base oils, one or more synthetic base oils, and a mixed oil of one or more mineral base oils and one or more synthetic base oils. The kinematic viscosity of the lubricating base oil used in the present invention is not particularly limited, but from the viewpoint of adapting to the damping force required for a general shock absorber, the lower limit value of the kinematic viscosity at 40 ° C is preferably S mn ^ Zs is more preferably S mn ^ Zs, while the upper limit is preferably 60 mm ² Zs, more preferably 40 mm ² X s, and even more preferably 20 mm ² Zs. In view of obtaining a frictional composition, it is more preferably 10 mm ² Zs or less, and particularly preferably S mn ^ Zs or less.

Also, the viscosity index of the lubricating base oil used in the present invention is not particularly limited and is arbitrary. However, the damping performance, which is a basic performance required for the shock absorber, depends on the viscosity of the hydraulic fluid and depends on the temperature. From the viewpoint of minimizing the change in reducing force, the viscosity index is preferably 80 or more, more preferably 95 or more. The component (A) in the hydraulic fluid composition for a shock absorber according to the present invention includes a phosphate ester having a hydrocarbon group having 3 to 30 carbon atoms, a phosphite ester, a phosphate esteramine salt having the hydrocarbon group, It is at least one selected from phosphite amine salts having hydrocarbon groups.

Specific examples of the component (A) include phosphoric acid esters represented by the general formula (1), phosphorous acid esters represented by the general formula (2), salts thereof, and mixtures thereof. Show.

^R1 O ヽ KU ⁰ (1)

ρ;

R ² 0, OR ³

In the above formula (1), R 1 ²及Pi 1 ³ are each independently a hydrocarbon group of a hydrogen atom or a carbon number 3-3 0, 1 at least one of R ¹ R ² and R ³ Tsugasumi It is a hydrocarbon group having a prime number of 3 to 30.

In the above formula (2), R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom or Is a hydrocarbon group having 3 to 30 carbon atoms, and at least one of R ⁴ , R ⁵ and R ⁶ is a hydrocarbon group having 3 to 30 carbon atoms.

Here, the hydrocarbon group may have one or more heteroatoms selected from a nitrogen atom, a sulfur atom, and an oxygen atom.

In the present invention, in order to increase the frictional force between the piston and the cylinder on which the fluororesin-based sliding material is mounted, the component (A) includes (A 1) having 3 to 10 carbon atoms. At least one selected from a phosphoric acid ester having a hydrocarbon group, a phosphorous acid ester, a phosphoric acid esteramine salt having the hydrocarbon group, and a phosphorous acid ester amin salt having the hydrocarbon group is used. It is done. Specifically, RR ² and R ³ in the formula (1) are each independently a hydrogen atom or a hydrocarbon group having 3 to 10 carbon atoms, preferably a carbon group having 4 to 8 carbon atoms. It is a hydrogen group, and at least one of R ¹ R ² and R ³ is a hydrocarbon group having 3 to 10 carbon atoms. In the above formula (2), R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom or a hydrocarbon group having 3 to 10 carbon atoms, preferably a hydrocarbon having 4 to 8 carbon atoms. And at least one of R ⁴ , R ⁵ and R ⁶ is a hydrocarbon group having 3 to 10 carbon atoms.

On the other hand, in the present invention, when reducing the frictional force between the piston and the cylinder on which the fluorine-based resin sliding material is mounted, the component (A) includes: (A 2) carbon number 11-30 (Hydroxy) phosphorus ester having a hydrocarbon group, preferably an alkyl group or alkenyl group, and (H) phosphate ester amine salt having the hydrocarbon group, preferably an alkyl group or alkenyl group. One kind is used. Specifically, R ¹ R ² and R ³ in the above formula (1) are each independently a hydrogen atom or a hydrocarbon group having 11 to 30 carbon atoms, preferably 12 to 24 carbon atoms, More preferably, it is a hydrocarbon group having 12 to 12 carbon atoms: I 8, and at least one of I ¹ , R ² and R ³ is a hydrocarbon group having 11 to 30 carbon atoms. R ⁴ , R ⁵ and R ⁶ in the above formula (2) are each independently a hydrogen atom or a hydrocarbon group having 11 to 30 carbon atoms, preferably an alkyl group or an alkenyl group, preferably carbon. A hydrocarbon group having 12 to 24 carbon atoms, more preferably 12 to 18 carbon atoms, and at least one of R ⁴ , R ⁵ and R ⁶ is a hydrocarbon group having 11 to 30 carbon atoms. . In the above formula (2), acidic phosphorous acid diester wherein R ⁶ is a hydrogen atom When R ⁵ and R ⁶ are acidic phosphorous acid monoesters in which hydrogen atoms are present, they must be represented by the following general formulas (3) and (4), which are tautomers, respectively. However, they represent the same compound.

^R4 V ⁰

R ⁵ 0 ^{/ X} H ( ³ ) 0, /

( Four )

HO ^X , H Specific examples of the hydrocarbon group having 3 to 10 carbon atoms include propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, Alkyl groups such as decyl groups (these alkyl groups may be linear or branched); probenyl groups, butenyl groups, pentenyl groups, hexenyl groups, heptul groups, octul groups, nonenyl groups, decenyl groups Alkenyl groups such as alkenyl groups (These alkenyl groups may be linear or branched, and the position of the double bond is arbitrary.); Carbon such as cyclopentyl group, cyclohexyl group, cyclopentyl heptyl group, etc. 5-7 alkyl groups; methyl cyclopentyl group, dimethylcyclopentyl group, methinoreethinorecyclopentyl group, jetylcyclopentinole group, methinorecyclohexenole group, An alkyl group having 6 to 10 carbon atoms such as dimethylcyclohexenole, methylethylcyclohexenole group, jetinolecyclohexenole group, methinorecycloheptyl group, dimethylcycloheptyl group, methylethylcycloheptyl group, etc .; Aryl group such as binole group, naphthyl group, etc .: each alkylaryl group having 7 to 10 carbon atoms such as tolyl group, xylyl group, ethenylphenyl group, propylphenyl group, butylphenyl group, etc. It may be linear or branched, and the substitution position is arbitrary.); Each arylalkyl group having 7 to 10 carbon atoms such as benzyl group, phenylethyl group, phenylpropyl group, phenylbutyl group, etc. These may be chain-like or branched, and the substitution position is also arbitrary).

Specific examples of the hydrocarbon group having 11 to 30 carbon atoms include an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, and a heptadecyl group. , Octadecyl group, Nonadecyl group, Icosyl group, Henry Alkyl groups such as kosyl group, docosyl group, tricosinole group, tetracosyl group, pentacosyl group, hexacosinole group, heptacosyl group, octacosyl group, nonacosyl group, triaconyl group (these alkyl groups may be linear or May be branched.); Undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, icoceninole group, hencocenylol group, dococenyl group Alkenyl groups such as tricosenyl group, tetracosenyl group, pentacocenyl group, hexacocenyl group, heptacosenyl group, octacosenyl group, nonacosenyl group, triacontyl group (these alkenyl groups are linear or branched) But it ’s good. The position of the combination is arbitrary.)

Further, as the above-mentioned salts of phosphoric acid esters and phosphites having 3 to 10 carbon atoms, specifically, acidic phosphoric acid monoesters having 3 to 10 carbon atoms, An ammonia diester, an acidic phosphorous acid monoester, an acidic phosphorous acid diester, etc., only have a hydrocarbon group having 1 to 30 carbon atoms, preferably 3 to 10 carbon atoms, or a hydroxyl group-containing hydrocarbon group. Examples thereof include nitrogen-containing compounds such as ammine compounds contained in the molecule, and salts obtained by neutralizing a part or all of the remaining acidic hydrogen by the action of metal or a metal base.

The phosphoric acid ester amin salt having an alkyl group or an alkenyl group having 11 to 30 carbon atoms, and the phosphite ester ammine salt having an alkyl group or an alkenyl group may include 11 to 11 carbon atoms. Although there is no particular limitation as long as it has a 30 alkyl group or an alkenyl group, specifically, an acidic phosphoric acid monoester having an alkyl group or alkenyl group having 3 to 10 carbon atoms, A part of the remaining acidic hydrogen by reacting an amine compound having an alkyl group or an alkenyl group having 11 to 30 carbon atoms with acid diester, acid phosphorous acid monoester, acid phosphorous acid diester, etc. Or a neutralized salt, an acidic phosphoric acid monoester, an acidic phosphoric acid diester, an acidic phosphorous monoester, an acidic sublimation having an alkyl group or an alkenyl group having 11 to 30 carbon atoms An amine compound containing only ammonia or a hydrocarbon group having 1 to 30 carbon atoms or a hydroxyl group-containing hydrocarbon group in the molecule is allowed to act on acid diester, etc., so that some or all of the remaining acidic hydrogen is Examples of such salts are: Specific examples of the nitrogen-containing compound include ammonia; monomethylamine, monoethinoreamin, monopropylamine, monobutinoreamin, monopentinoreamin, monohexylamine, monoheptylamine, and monooctylamine. , Mononoelamine, monodecylamine, monoundecylamine, monododecylamine, monotridecylamine, monotetradecylamine, monopentadecylamine, monohexadecylamine, monoheptadecylamine, monooctadecylamine, Monoethenoreamin, ¾nopropenoreamin, mononobutenoreamin, monopentenoreamin, monohexenylamine, monoheptenyl / reamin, monooctenylamine, monononenylamine, monodecenylamine Mines, monoundecenylamine, monododecenylamine, monotridecenylamine, monotetradecenylamine, monopentadecenylamine, monohexadecenylamine, monoheptadecenylamine, monooctadecenylamine, dimethylamine Methylethylamine, jetylamine, methinorepropylamine, ethylpropylamine, dipropylamine, methylbutanolamine, butylbutylamine, propylbutylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, diheptylamine, etc. (The alkyl group and alkenyl group may be linear or branched, and the position of the double bond of the alkenyl group is arbitrary.); Monomethanolamine, Monoeta -Noramine, Monoprononorenolemine, Monobutanolamine, Monopentanolanolamine, Monohexanolamine, Monoheptanolamine, Monooctanolamine, Monononanolamine, Dimethanolamine, Methanolanol , Ethanolanol, methanololamine, ethanolamine / lebropananolamine, dipropanolamine, methanolinobutanolamine, ethanolanolamine, propanolbutanolamine, Alkanolamines such as dibutanolamine, dipentanolamine, dihexanolamine, diheptanolamine, dioctanolamine, etc. (The alkyl group may be linear or branched. ); And a mixture thereof.

In the present invention, among these components (A), the frictional force between the piston fitted with the fluororesin-based sliding material and the cylinder can be stably controlled to a required level. Phosphoric acid esters, acidic phosphorous acid esters, phosphoric acid triesters, and phosphorous acid phosphoric acid esters are preferred, and acidic phosphoric acid esters and acidic phosphorous acid esters are preferred. Acid phosphite is particularly preferred in the present invention. In the present invention, when increasing the frictional force between the viston and the cylinder on which the fluororesin-based sliding material is mounted, particularly preferred acidic phosphite. Esters include monoisobutylhydrogen phosphate, diisobutylhydrogen phosphate, and mono-2-ethynolehexylhydride, which can adjust the durability and friction characteristics of the shock absorber. And acid phosphites having a branched alkyl group having 4 to 8 carbon atoms, such as di2_ethylhexylhydrogen phosphate, and mixtures thereof. These compounds increase the frictional force between the piston and the cylinder fitted with a fluororesin-based sliding material, and increase the damping force at the neutral position of the shock absorber. ) Is effective in reducing the driver's and passengers' discomfort.

On the other hand, in the present invention, when reducing the frictional force between the piston and the cylinder on which the fluororesin-based sliding material is mounted, the particularly preferable acidic phosphite is the durability of the buffer, the friction Monolauryl Hydrogen Phosphite, Dilauryl Hydrogen Phosphite, Monostearyl Hydrogen Phosphate, Disteari ^ Lehai Drogen Phosphate, Monooleno Lehidrogen Phosphate Phosphate, Gioleil High Examples thereof include acidic phosphite having a C1-C18 alkyl group or alkenyl group such as drogen phosphate and a mixture thereof. These compounds are effective in lowering the frictional force between the piston rod seals as well as reducing the frictional force between the piston and the cylinder fitted with the fluororesin-based sliding material. is there. The content of the component (ii) in the present invention is not particularly limited, but the effect of preventing the wear of the cylinder while stably constricting the friction between the fluorine-based composite material and the cylinder. From the viewpoint of the total amount of the composition, it is preferably 0.05 to 0.2% by mass, more preferably 0.01 to 0.1% by mass, particularly preferably in terms of phosphorus element. Is 0.01 5 to 0.06 mass. / ₀ . (Ii) If the content of the component is too small, the effect of preventing wear is small, and even if it exceeds 0.2% by mass, it is difficult to obtain an effect commensurate with the content and tends to cause corrosion and deterioration. It is in. The component (B) in the hydraulic fluid composition for a shock absorber according to the present invention is a glycerin ester of a saturated or unsaturated fatty acid having 6 to 30 carbon atoms, and the triester is 10% by mass or less based on the total amount of the ester. An ester having a mass ratio of monoester to the sum of monoester and diester of 0.5 or more. By including the component (B), it is possible to maintain the initial frictional force between the fluorine-based composite material and the cylinder for a long period of time.

The fatty acid may be a linear fatty acid or a branched fatty acid, may be a saturated fatty acid or an unsaturated fatty acid, and may be a monobasic acid or a polybasic acid. Specific examples of the fatty acid include hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, and hexadecane. Saturated fatty acids having 6 to 30 carbon atoms, preferably 12 to 18 carbon atoms, such as acids, heptadecanoic acid, and octadecanoic acid (these may be linear or branched); dodecenoic acid, tridecenoic acid Unsaturated fatty acids having 6 to 30 carbon atoms, preferably 12 to 18 carbon atoms, such as tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, heptadecenoic acid and octadedecenoic acid (these are linear or branched) The position of the double bond is also optional.); Dodecyl succinic acid, tridecyl succinic acid, tetradecyl succinic acid, pentadecyl succinic acid, hexadecyl succinic acid, Saturated dibasic fatty acids having 6 to 30 carbon atoms, preferably 12 to 18 carbon atoms, such as heptadecyl succinic acid and octadecyl succinic acid (these may be linear or branched); dodecenyl succinic acid, Rideceninosuccinic acid, Tetradecenyl succinic acid, Pentadecenino succinic acid, Hexadecenyl succinic acid, Heptadecenyl succinic acid, Octadecenyl succinic acid, etc. 6 to 30 carbon atoms, preferably carbon And an unsaturated dibasic fatty acid having a number of 1 to 18 (which may be linear or branched, and the position of the double bond is arbitrary). Of these, saturated or unsaturated monobasic fatty acids having 12 to 18 carbon atoms such as lauric acid, stearic acid, and oleic acid are particularly preferable.

The glycerin ester of a saturated or unsaturated fatty acid having 6 to 30 carbon atoms in the present invention (B) has a triester ratio in the glycerin ester of 10% by mass or less, preferably 1% by mass or less. The monoester ratio is 0.5 or more, preferably 0.7 or more, particularly preferably 0.7 or more by mass ratio with respect to the sum of monoester and diester. It is desirable to refine it to 9 or more and increase the monoester ratio. The glycerol ester of a saturated or unsaturated fatty acid in the present invention is preferably 90% by mass or more, more preferably 95% by mass of a monoester. Those containing at least ₀ are most preferable.

In the present invention, (B) a method for producing a glycerol ester of a saturated or unsaturated fatty acid having 6 to 30 carbon atoms is not particularly limited. For example, 1,2-isopropylideneglycerin and a fatty acid glyceride are used. After reacting, it can be obtained by selective synthesis by a chemical method such as acid decomposition, or it can be obtained by separating and purifying only the monoester from a mixture containing mono, di and triesters. . Examples of the mixture containing a monoester used here include a glycerin partial fatty acid ester produced by a direct esterification reaction between a fatty acid and glycerin, a transesterification reaction between an oil and fat and glycerin, and the like. As a separation and purification method, it is preferable to purify using a molecular distillation apparatus or a thin film distillation apparatus. In addition, since glycerin has three hydroxyl groups, glycerin fatty acid monoester has two isomers, that is, the α-position hydroxyl group and the J3-position hydroxyl group. However, in the present invention, either isomer or a mixture of these isomers may be used.

The content of the component (ii) in the present invention is not particularly limited, but is usually from 0.1 to 5% by mass, preferably from 0.05 to 2% by mass, particularly preferably from 0 to 5% by mass based on the total amount of the composition. 1 to 1% by mass. (Ii) If the content of the component is less than 0.01% by mass, it is difficult to maintain the initial friction characteristics, and if it exceeds 5% by mass, the effect corresponding to the content cannot be obtained, and storage is not possible. It tends to be inferior in stability. The hydraulic fluid composition for a shock absorber according to the present invention preferably further contains (C) a basic nitrogen-containing compound.

Examples of the (C) basic nitrogen-containing compound include basic compounds having an alkyl group or alkenyl group having 8 or more carbon atoms and a basic polar group. The basic polar group here is not particularly limited, and examples thereof include nitrogen-containing polar groups such as amino group, imino group and amide group, and modified groups thereof.

(C) Specific examples of basic nitrogen-containing compounds include amine compounds and derivatives thereof having at least one alkyl group or alkenyl group having 8 or more carbon atoms in the molecule. Can be mentioned. More specifically, (C 1) an amine compound having an alkyl group or alkenyl group having 8 to 30 carbon atoms or a derivative thereof, and (C 2) an alkyl group or alkenyl having 31 to 400 carbon atoms. Examples thereof include amine compounds having a group and derivatives thereof.

More specifically, as the (C 1) component,

(C 1-1) an aliphatic monoamine represented by the following general formula (8) or an alkylene oxide adduct thereof,

(C 1-2) Aliphatic polyamine and its derivative represented by the following general formula (9), (C 1-3) Succinic acid represented by the following general formula (1 0) or (1 1) ( Anhydride)

—Polyamine reaction products and derivatives thereof,

(C 1-4) imidazoline compounds represented by the following general formula (12) and derivatives thereof, (C 1-5) having at least one alkyl group or alkenyl group having 8 to 30 carbon atoms. Fatty acid amide compounds,

(C 1-6) Sarcosine or its derivative represented by the following general formula (5) or (6)

Etc.

More specifically, as the component (C 2),

(C2-1) succinic acid (anhydride) having a C1-C40 alkyl group or alkenyl group, one polyamine reaction product and its derivative,

(C2-2) a polyamine having an alkyl group or an alkenyl group having 31 to 40 carbon atoms and a derivative thereof,

(C2-3) a benzylamine having an alkyl group or an alkenyl group having 31 to 40 carbon atoms and a derivative thereof,

And high molecular basic compounds such as

In the general formula (8), R ^{1 3} is 8-3 carbon atoms 0, preferably an alkyl or alkenyl group of 1. 2 to 24, R ^{1 4} and R ^{1 5} are each independently, 1 to 4 carbon atoms -4, preferably 2-3 alkylene groups, R ¹⁶ and R ¹⁷ are each independently hydrogen or a hydrocarbon group having 1 to 3 carbon atoms, and a and b are each individually Represents an integer of 0 to 10, preferably 0 to 6, and a + b-0 to: 1 0, preferably an integer of 0 to 6.

In the general formula (9), R ¹⁸ represents an alkyl group or an alkenyl group having 8 to 30 carbon atoms, preferably 12 to 24 carbon atoms, and R ¹⁹ represents 1 to 4 carbon atoms, preferably 2 to 3 carbon atoms. Represents an alkylene group, R ^{2 G} and R ²¹ each independently represent hydrogen or a hydrocarbon group having 1 to 30 carbon atoms, and c represents an integer of 1 to 5, preferably 1 to 4.

In formula (1 0) and (1 1), R ²² and R ²³ are each independently 8 carbon atoms 3.0, preferably an alkyl or alkenyl group of 1 2-24 carbon atoms, R ²⁴ And R ²⁵ each independently represents an alkylene group having 1 to 4 carbon atoms, preferably 2 to 3 carbon atoms, and R ²⁶ is a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, preferably 8 to 30 carbon atoms. A group or an alkenyl group, n represents an integer of 1 to 7, and preferably an integer of 1 to 3. RR ²⁸ . _{(i 2)}

In the general formula (1 2), R ²⁷ is 8 carbon atoms 3 0, preferably an alkyl or alkenyl group of 1 2~ 24, R ^{2 8} is shows the ethylene or propylene group, R ²⁹ is It represents hydrogen or a hydrocarbon group having 1 to 30 carbon atoms, and d represents an integer of 0 to 10 and preferably 0 to 6.

In the general formula (5), R ⁷ and R ⁸ each independently represent hydrogen, an alkyl group or an alkenyl group having 1 to 30 carbon atoms, and R ⁹ represents a single bond or an alkylene group having 1 to 4 carbon atoms. Show. In the present invention, a single bond means a direct bond, and here, R ⁹ does not exist, meaning that nitrogen and carbon are directly bonded.

R—C II—Ν l _n — RC II—ΟΗ (6) In the above general formula (6), R ¹⁰ and R ¹¹ are each independently hydrogen or an alkyl group or alkenyl having 1 to 30 carbon atoms. R ¹ represents a group. And at ^{least one} of R ¹¹ is an alkyl group or alkenyl group having 8 to 30 carbon atoms, and R ¹² represents a single bond or an alkylene group having 1 to 4 carbon atoms.

In the above, the alkyl group or alkenyl group having 8 to 30 carbon atoms may be linear or branched, preferably a linear or branched alkyl group having 12 to 24 carbon atoms. Or an alkenyl group, for example, a linear or branched dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, Group, docosyl group, tricosyl group, tetracosyl group, dodecenyl group, tridecenyl group, tetradecenyl group, pentadecenyl group, hexadecenyl group, heptadecenyl group, octadecenyl group, nonadecenyl group, icosenyl group, hencocenyl group , Dococenyl group, tricocenyl group, tetracocenyl group and the like. These That is, a lauryl group, a myristyl group, a palmityl group, a stearyl group, an oleyl group, and the like are particularly preferable from the viewpoint of excellent friction adjustment effect.

In the above, the hydrocarbon group having 1 to 30 carbon atoms includes an alkyl group having 1 to 30 carbon atoms, an alkyl group, a cycloalkyl group, an anolenoquinocycloalkynole group, and an allyl group. And alkylaryl groups and arylalkyl groups. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, Alkyl groups such as pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group, tricosyl group, tetracosyl group, etc. (These alkyl groups may be linear or branched. ; Butle group, propenyl group, budul group, pentenyl group, hexenyl group, heptul group, otatur group, nonenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, tetradecenyl group , Pentadecenyl group, hexadecenyl group, heptadecenyl group, octa Alkenyl groups such as senyl group, nonadecenyl group, icosenyl group, hencocenyl group, dococenyl group, tricocennole group, tetracosenyl group, etc. (These alkenyl groups may be linear or branched, and the position of the double bond is ); Cyclopentyl group, cyclohexyl group, cycloheptinole group, etc .; cyclopentyl group, cyclohexyl group, etc .; methylcycline pentyl group, dimethylcycline pentyl group, methylethinorecyclopentyl group, jetylcyclopentyl group, methylcycline Xyl group, dimethylcyclohexyl group, methylethylcyclohexyl group, dimethylcyclohexenole group, methinorecycloheptyl group, dimethylcycloheptyl group, methylethylenocyclyl heptyl group, jetylcyclyl heptyl group, etc. Alkyl groups of alkyl groups (all Including aryl isomers); aryl groups such as phenyl and naphthyl groups; tolyl groups, xylinole groups, ethenyl phenyl groups, propyl phenyl groups, butyl phenyl groups, pentyl phenyl groups, hexyl phenyl groups, heptyl phenyls Group, octylphenyl group, nourphenyl group, decylphenyl group, undecylphenyl group, alkyldecyl group such as dodecylphenyl group (including all structural isomers); benzyl group, phenylenotinole group, phenyl Arylalkyl groups such as propyl group, phenylbutyl group, phenylpentyl group, phenylhexyl group (including all structural isomers). ) Etc. are mentioned. (CI 1 1) As the aliphatic monoamine represented by the above formula (8) or an alkylene oxide adduct thereof, R ¹⁶ and R ¹⁷ in formula (8) are Respectively, hydrogen or an aliphatic monoamine having 1 to 6 carbon atoms and _a = b = 0, R ¹⁶ and R ¹⁷ are hydrogen, and a and b are each Individually, an alkylene oxide adduct of an aliphatic monoamine having a number of 0 to 6 and a + b = 1 to 6 is more preferably used, and the fat is particularly excellent in the friction adjustment effect. Particularly preferred are group monoamines.

Further, (C 1 - 2) the formula with aliphatic Poriamin represented by (9), from the viewpoint of excellent friction adjustment effect, in the formula (9), R ^{2 Q,} and R ^{2 1} are each individually, hydrogen or an aliphatic polyamine is an alkyl group having a carbon number of 1-6 is more preferred, aliphatic Poriamin R ^{2 Q,} and R ^{2 1} is hydrogen are particularly preferred. The substitution position of the amino group is preferably at the terminal carbon of the alkyl group, but may be one carbon inside the terminal.

In addition, (C 1-3) is a succinic acid (anhydride) -polyamine reaction product represented by the above formula (10) or (11). Bis-type succinic acid wherein R ²² and R ²³ are alkyl or alkenyl groups having 12 to ¹⁸ carbon atoms, and R ²⁴ and R ²⁵ are alkylene groups having 1 to 4 carbon atoms. Do, expression

(1 1) R ²² is an alkyl or alkenyl group having 1 2-1 8 carbon atoms in, R ² ⁴ is C 1-4 alkylene group, R ²⁶ is succinic acid mono-i Mi de a hydrogen atom Is particularly preferably used.

Further, as the (C 1 one 4) Lee Midazori emission compound represented by the formula (1 2), from the viewpoint of excellent friction adjustment effect, R ^{2 9} in the formula (1 2) is hydrogen or carbon An imidazoline compound having an alkyl group of 1 to 6 is more preferably used.

Further, (C1_5) fatty acid amide compound having at least one alkyl group or alkenyl group having 8 to 30 carbon atoms is specifically an alkyl having 8 to 30 carbon atoms. A nitrogen-containing compound such as ammonia, an amine compound containing only a hydrocarbon group having 1 to 30 carbon atoms or a hydroxyl group-containing hydrocarbon group in a molecule thereof, and a fatty acid having a alkenyl group or an acid chloride thereof. Examples include fatty acid amides obtained.

Specific examples of the nitrogen-containing compounds include nitrogen-containing compounds such as the amine compounds mentioned in the section of (A) phosphoric acid ester amine salt, which is one of the components (A). Et It is.

Specific examples of the fatty acid amide compound include lauric acid amide, lauric acid diethanol amide, lauric acid monopropanol amide, and myristic acid amide because of its excellent friction reducing effect. , Myristic acid diethanol amide, myristic acid monopropanol amide, panolemitic acid amide, palmitic acid diethanol amide, palmitic acid monopropanol amide, stearic acid amide, stearic acid jetanolamide, stearic acid mono Propanol amide, oleic acid amide, oleic acid diethanol amide, oleic acid monopropanol amide, coconut oil fatty acid amide, coconut oil fatty acid diethanol amide, coconut oil fatty acid monopropanol amide, carbon number 1-23-1 Synthetic mixed fatty acid amide, carbon A synthetic mixed fatty acid diethanolamide having a number of 12 to 13, a synthetic mixed fatty acid monopropanol amide having a carbon number of 12 to 13 and a mixture thereof are particularly preferably used.

In addition, as (C 1-6) sarcosines, at least one of R ⁷ and R ⁸ in the general formula (5) is an alkyl group having 8 to 30 carbon atoms, preferably 12 to 24 carbon atoms. Or an alkenyl group, and examples of the sarcosine derivatives include carboxylic acids having 8 to 30 carbon atoms, preferably 12 to 24 carbon atoms, including the sarcosine represented by the general formula (5). And a compound represented by the general formula (6) in which R ⁷ is hydrogen and R ⁸ is methyl. A sarcosine derivative obtained by reacting a sarcosine group in which R ⁹ is a methylene group with a carboxylic acid having an alkyl group or an alkenyl group having 8 to 30 carbon atoms such as oleic acid or stearic acid. preferable.

In addition, R ¹¹ in the general formula (6) is preferably hydrogen or 1 to 4 carbon atoms, and particularly preferably a methyl group.

In addition, R ¹² in the general formula (6) is preferably a single bond or 1 to 4 carbon atoms, and particularly preferably a methylene group.

In the present invention, particularly preferred specific examples of the compound represented by the general formula (6) include N-oleoyl sarcosine represented by the formula (7).

CH ₃ (CH ₂ ) ₇ CH = CH (CH ₂ ) ₇ ― C— N— CH ₂ —C— OH (7)

0 CH ₃ O In the present invention, among these (C 1) components, laurylamine, lauryljetylamine, lauryldiethanolamine, dodecy / resipropanolamine, palmitylamine, stearylamine are preferred because of their excellent friction characteristics. , Stearyl tetraethylenepentamine, oleylamine, oleylpropylene diamine, oleyljetanolamine, oleyl succinic acid imide, isosteric linoleic acid imide, N-hydroxetyl Amine compounds such as oleirid midazoline; alkylene oxide adducts of these amine compounds such as stearylamine ethylene oxide adducts; sarcosine derivatives such as N-oleoyl sarcosine or mixtures thereof Preferably used. In addition, (C 2-1) succinic acid (anhydride) monopolyamine reaction product having an alkyl group or an alkenyl group having 31 to 40 carbon atoms includes the above formulas (1 0) and (1

1), R ^{2 2} and R ^{2 3} are alkyl groups or alkenyl groups having 3 to 4 to 400, preferably 4 to 4 and more preferably 4 to 3 50 carbon atoms. And (C2-2) as a polyamine having an alkyl group or an alkenyl group having 31 to 40 carbon atoms, R ¹⁸ in the above formula (9) has 31 to 4 carbon atoms. Examples include polyamines that are alkyl groups or alkenyl groups having 0 to 40, preferably 40 to 40, more preferably 40 to 35, and (C2-3) having 31 to 40,000 carbon atoms, When the acidic additive in the composition is excessive together with benzylamine having an acrylyl group or an alkenyl group of preferably 40 to 400, more preferably 40 to 35, the wear of the composite material and In order to prevent breakage, and further these alkyl group or alkenyl group having 31 to 40 carbon atoms The basic compound having the formula is useful as an additive for dispersing a deteriorated product in the composition.

On the other hand, as the derivative of the amine compound, specifically, for example, an amine compound such as the above formulas (8) to (12), an alkyl group having 3 to 400 carbon atoms, or an alkenyl group. Succinic acid (anhydride) with 1 polyamine reaction product, ammine or benzylamine, etc., monocarboxylic acid having 2 to 30 carbon atoms (fatty acid, etc.), oxalic acid, phthalic acid, trimellit A part of or all of the remaining amino groups and Z or imino groups are neutralized by the action of polycarboxylic acid having 2 to 30 carbon atoms such as acid or pyromellitic acid, or amido formation. So-called acid-modified compounds; amine compounds such as formulas (8) to (12) Or succinic acid (anhydride) having a C1-C40 alkyl group or an alkenyl group, a polyamine reaction product, amine or benzylamine, and boric acid to act on the remaining amino group and / or A so-called boric acid-modified compound obtained by neutralizing part or all of the mino group; having an amine compound such as formulas (8) to (12) or an alkyl or alkenyl group having 3 to 40 carbon atoms Succinic acid (anhydride)-polyamine reaction product, amine or benzylamine reacted with alkylene oxide such as ethylene oxide propylene oxide, so-called alkylene oxide adduct of amine compound; And a modified compound of an amine compound obtained by combining two or more selected modifications. In the present invention, when reducing the frictional force between the piston and the cylinder on which the fluororesin sliding material is mounted, the component (C) is selected from the various basic compounds described above. One or more types can be used, but at least one selected from the (C 1) component can be used because the friction between the fluorine-based composite material and the cylinder can be controlled at a lower level. It is preferable to use, and among them, it is more preferable to use at least one selected from the components (C 1 1 1), (C l _ 2), (C 1-3) and (C 1-6). It is particularly desirable to use at least one selected from the components (C 1 1 1) and (C 1 1 3). On the other hand, in the present invention, the component (C 2) is preferably used as the component (C) when increasing the frictional force between the piston on which the fluororesin sliding material is mounted and the cylinder.

In this case, there is no particular limitation on the ratio of the imino group and the amino group in the component (C 2). For example, it is 0 for a compound that does not contain an imino group such as ethylenediamine mono (alkenyl) succinic acid imide. A compound that does not contain an amino group such as diethylenetriaminebis (alkenyl) succinic acid imide can be infinite, but is preferably 0.1 to 50 from the viewpoint of production cost. In addition, the ratio of imino group and nonamino group is preferably 30 or less from the viewpoint of obtaining a higher-fractionation composition, and preferably 1 from the viewpoint of stability and production cost. That's it.

In the present invention, between the silicon and the cylinder fitted with the fluororesin sliding material From the viewpoint of increasing the frictional force, it is particularly preferable to use a (C2-1) succinic acid imide (anhydride) monopolyamine reaction product having an imino group / amino group ratio of 1 to 30. The imino group Z amino group ratio of the component (C 2-1) is preferably 2 to 2 in terms of high friction between the fluororesin sliding material and the cylinder. 0, more preferably 3.5 to 15, more preferably 9 to 15, and particularly preferably 1 0.5 to 14. In addition, the component (C 2-1) may or may not contain boron. However, boron is highly effective in controlling the friction between the fluorine-based sliding material and the cylinder. It is preferable not to contain essentially. Here, the imino group is a group represented by 1 NH—, the amino group is a group represented by NH ₂ and the imino group Z amino ratio is the amino acid in the component (C). Base

It represents the ratio of the nitrogen atom composing the imino group (—NH—) in the component (C) to the nitrogen atom composing (1 NH ₂ ).

Specifically, the imino group and the amino group and the ratio thereof can be obtained by the following method.

(C) A reaction product obtained by reacting a compound having an imino group and a no- or amino group with trifluoroacetic anhydride, such as component (C), is standardized with trifluoroacetic acid when subjected to ¹⁹ F-NMR. As a substance, when the peak position is set to 1 6.8 ppm,

Peaks can be obtained at (a) chemical shifts at 6 6 ppm and 7 2 ppm and (b) chemical shifts at 74 and 7 9 ppm. The peak of (a) is obtained by the reaction of imino group (1NH-) in component (C) with trifluorosuccinic anhydride as shown in the following formula (I). The peak of (b) is obtained by reacting the amino group (one NH ₂ ) in component (C) with trifluoroacetic anhydride as shown in the following formula (iii): It is presumed to show the peak of the group represented by (i).

— OH

-NH ₂ +

The procedure for reacting the component (C) with trifluoroacetic anhydride and the measurement procedure by ¹⁹ F-NMR are as follows.

First, 0.5 g of component (C) is dissolved in 20 ml of hexane, 1.0 g of trifluoroacetic anhydride is added thereto, and the mixture is reacted at 20 ° C. for 20 minutes with stirring. Thereafter, 10 ml of methanol and 0.5 ml of concentrated hydrochloric acid were added to the reaction product, and stirring was continued at 20 for 20 minutes. Unreacted trifluoroacetic anhydride and reaction by-product trifluoroacetic acid were added to the methanol layer. Remove. Next, the oil layer is taken out, and hexane is distilled off by distillation to obtain a reaction product of component (C) and trifluoroacetic acid. Using 100 mg of the reaction product thus obtained as a sample, it is analyzed by ¹⁹ F-NMR at a resonance frequency of 564. 4 MHz.

That is, the imino group “amino group ratio in the component (C) is a value specified by the ratio of the peak area of the above (a) to the peak area of the above (b) obtained by this method, that is, (C ) Means the ratio of the nitrogen atom constituting the amino group (one NH-) in the component (C) to the nitrogen atom constituting the amino group (one NH ₂ ) in the component, but similar results May be used, another measurement method using the same theory, etc. In the hydraulic fluid composition for a shock absorber of the present invention, the content of component (C) is based on the total amount of the composition. In general, it is 0.001 to 10% by mass, preferably 0.01 to 5% by mass, more preferably 0.1 to 2% by mass (A) The amount of the component is If the amount is less than 0.001% by mass, the effect of adding the component (C) will not be exhibited, and even if it exceeds 10% by mass, it will only meet the blending amount. Effect can not be obtained, which is undesirable economically. (C) content of the nitrogen content of the component is preferably 0.00 1% by mass or more, more preferably 0.0 0 2 wt. / ₀ or more Particularly preferably, it is 0.005% by mass or more, and an effect corresponding to the content cannot be obtained, and the low-temperature characteristics tend to deteriorate. Therefore, preferably 0.2% by mass or less, More preferably 0.05% by mass or less, particularly preferably 0.0 1% by mass or less. In addition, when the component (C) containing boron, for example, the component (C) containing boron, is contained, the content of boron is usually 0.001 to 0.2 mass ⁰ / ₀ , preferably from 0.02 to 0.05 mass%, more preferably from 0 to 1 mass% in terms of stability in the presence of component (A), particularly preferably 0 It is desirable to make it 008% by mass or less.

In addition, the blending ratio with the (A) component when blending the (C) component is not particularly limited, but the mass ratio of the amount of nitrogen due to the (C) component to the amount of phosphorus due to the (A) component (N ZP ratio) is preferably from 0.01 to 2, preferably from 0.05 to 5 in terms of enhancing the durability of the fluororesin-based sliding material and enabling stable control of the friction characteristics. 1.5. In addition, in the hydraulic fluid composition for shock absorbers of the present invention, when the frictional force between the piston fitted with the fluororesin-based sliding material and the cylinder is increased, the components (A 1), (C 2) and It is desirable to use together as a main component. In this case, the mass ratio (NZP ratio) of the (C 2) component-derived nitrogen amount to the (A 1) component-derived phosphorus amount (NZP ratio) increases the friction between the fluorine-based composite material and the cylinder at a higher level. From the point that it can be controlled over a period, it is preferably 0.01 to 2, more preferably 0.05 to 1, more preferably 0.1 to 0.7, still more preferably 0.:! ˜0.5, particularly preferably 0.1 to 0.3.

In addition, in the hydraulic fluid composition for shock absorbers of the present invention, when reducing the frictional force between the piston and fluorocarbon resin-based sliding material, the components (A 2) and (C 1) It is desirable to use it as a main component. In this case, the mass ratio (NZP ratio) of the (C 1) component-derived nitrogen amount to the (A 2) component-derived phosphorus amount (NZP ratio) is a lower level of friction between the fluorine-based composite material and the cylinder. In view of long-term control, it is preferably from 0.01 to 2, more preferably from 0.1 to 1.5, more preferably from 0.2 to 1.2, and even more preferably from 0.5 to : I.1, particularly preferably 0.8 ~! It is. The hydraulic fluid composition for a shock absorber according to the present invention contains the component (A) and the component (B), or further contains the component (C), so that the piston and the cylinder, in particular, the fluororesin-based composite material is contained. The friction coefficient between the installed piston and the cylinder It controls at the required level according to the purpose of the shock absorber, maintains its friction characteristics for a long period of time, and maintains the riding comfort designed at the beginning. In order to further improve its performance, or according to other purposes, any additive generally used in lubricating oils can be added. Examples of such additives include friction modifiers other than the components (A) and (B), viscosity index improvers, antiwear agents, antioxidants, fluidity improvers, and metal inactivity. In addition to agents, antifoaming agents, various additives such as metal detergents, corrosion inhibitors, antifungal agents, demulsifiers, and coloring agents can be mentioned.

As the friction modifier other than the component (A) and the component (B), any compound usually used as a friction modifier for lubricating oil can be used. For example, molybdenum dithiocarbamate molybdenum dithiophosphine. Having at least one straight chain alkyl group or straight chain alkenyl group having 6 to 30 carbon atoms, particularly a straight chain alkyl group or straight chain alkenyl group having 6 to 30 carbon atoms. Ashless friction modifiers such as fatty acids, aliphatic alcohols, aliphatic ethers, esters of monovalent or polyhydric alcohols other than glycerin with 6 to 30 carbon atoms. It can be contained in the range of 0.001 to 5% by mass on the basis.

As the viscosity index improver, any compound that is usually used as a viscosity index improver for lubricating oils can be used. For example, one or two or more monomers selected from various methacrylates can be used. A so-called non-dispersed viscosity index improver such as a polymer or copolymer or a hydrogenated product thereof, or a so-called dispersed viscosity index improver obtained by copolymerizing various methacrylate esters containing a nitrogen compound. Type or dispersed ethylene-α-olefin copolymers (Examples of α-olefin include propylene, 1-butene, 1-pentene, etc.) or hydrides thereof, polyisobutylene Examples thereof include a hydrogenated product thereof, a hydride of a styrene monogen copolymer, a styrene monoanhydride maleate ester copolymer, and a polyalkylstyrene.

The number average molecular weight of the viscosity index improver is, for example, usually 5, 0 0 0 to: 1, 0 0 0, 0 0 0, preferably 1 0 0 in the case of dispersed and non-dispersed polymethacrylates. , 0 0 to 9 0 0, 0 0 0 is polyisobutylene or a hydride thereof, usually 8 0 0 to 5, 0 0 0, preferably 1, 0 0 0 to 4, 0 0 0 When the substance is an ethylene-α-olefin copolymer or a hydride thereof, usually 80 0 to 5 0 0, 0 0, preferably 3, 0 0 0 to 2 0 0, 0 0 0 are used. One or two or more compounds arbitrarily selected from the above viscosity index improvers can be contained in any amount. The content of the viscosity index improver is generally from 0.1 to 2 0 mass ^_0/0 of the total amount of the composition.

As the antioxidant, any compound usually used as an antioxidant for lubricating oils can be used. For example, 2, 6-di-tert-petite rho-cresol, 4, 4'-methylene bis (2, 6-di-tert-butylphenol), octyl-3— (3,5-ditert-butyl-4-hydroxyphenyl) Probione, 3-methyl-5-tert-butyl-4-hydroxyl Examples thereof include phenolic antioxidants such as binole substituted fatty acid esters, and amine antioxidants such as phenyl-α-naphthylamine, alkenylphenyl-α-naphthylamine, and dialkyldiphenylamine. These antioxidants can be contained in the composition of the present invention usually in the range of 0.01 to 5% by mass based on the total amount of the composition.

As the fluidity improver, any compound usually used as a fluidity improver for lubricating oils can be used, and examples thereof include polymetalate fluidity improvers. .

Examples of metal deactivators include imidazoline, pyrimidine derivatives, alkyl thiadiazoles, mercaptobenzozoazoles, benzotriazol or derivatives thereof, 1, 3, 4-thiadiazole polysulfide, 1, 3, 4— And thiadiazolyl 2,5-bisdialkyldithiocarbamate, 2 — (alkyldithio) benzimidazole, and] 3 — (ο-carboxybenzylthio) propiononitrile.

Examples of the antifoaming agent include silicone, fluorosilicol, and fluoroalkyl ether. ,

Examples of the metal detergent include sulfonate, finate, salicylate, and phosphonate of Al-strength metal or ar-strength earth metal.

Examples of the corrosion inhibitor include benzotriazole series, tritriazole series, thiadiazole series, and imidazole series compounds.

Examples of the antifungal agent include petroleum sulfonate, alkylbenzene sulfonate, dinonylnaphthalene sulfonate, alkenyl succinate, and polyvalent alcohol. Examples include coal esters.

Examples of the demulsifier include polyalkylene dallicol-based nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylene alkyl naphthyl ether. Can be mentioned. .

When these additives are contained in the hydraulic fluid composition for shock absorbers of the present invention, the content is based on the total amount of the composition, and a fluidity improver, metal detergent, corrosion inhibitor, antifungal agent, For demulsifiers, 0.05 to 5 masses each. /. The metal deactivator is usually selected in the range of 0.05 to 1% by mass, and the antifoaming agent is usually selected in the range of 0.05 to 1% by mass.

[Industrial applicability]

The hydraulic fluid composition for a shock absorber according to the present invention reduces the frictional force between the piston and the cylinder in the shock absorber, particularly between the piston and the cylinder fitted with the fluororesin-based composite material, depending on the purpose of the shock absorber. Alternatively, high control can reduce the vibration of the vehicle body and improve ride comfort and handling stability. In particular, by controlling the frictional force high, the damping force at the neutral position of the shock absorber is increased, and the vehicle body at fine amplitude

(Sprung load) fluctuations can be suppressed, and driver and passenger discomfort can be reduced. And the initial friction characteristics designed to meet the purpose of the shock absorber can be maintained for the life of the shock absorber.

[Best Mode for Carrying Out the Invention]

Hereinafter, although the content of the present invention is explained more concretely by an example and a comparative example, the present invention is not limited to these at all.

Lubricating oil compositions (Examples 1 to 5) and comparative lubricating oil compositions (Comparative Examples 1 to 8) according to the present invention in which additives having the compositions shown in Tables 1 to 2 are blended with lubricating base oils Were prepared respectively. These compositions were subjected to the following friction tests, and the results are shown in Tables 1 and 2. (Friction test)

Using an S RV friction tester, put a composite material with a thickness of about 0.8 mm and a fluororesin component containing graphite into a cylindrical jig that is fixed so that the lower part of the test steel ball is exposed. A test steel ball was press-fitted from above and fixed so that the sliding portion of the composite material was exposed in a hemispherical shape. Set a test steel disk as the sliding material of the other party, drop a few drops of test oil on it, conduct a friction test at 110 ° C under a constant overload condition, and determine the initial friction coefficient (average value: 0 00) and the time until the friction coefficient increased to 0.05 was measured.

As is clear from the results in Tables 1 and 2, the composition containing the components (A) and (B) of the present invention can control the initial friction coefficient to a low level and stably maintain the friction coefficient. It can be maintained stably for a longer time by adding component (C). On the other hand, a composition containing no component (A) or (B), and a composition containing a fatty acid ester that does not satisfy the provisions of the component (B) in place of the component (B) (Comparative Examples 1 to 8) ) Shows that the coefficient of friction increases in a short time and it is difficult to maintain the initial low coefficient of friction.

Lubricating oil compositions according to the present invention in which additives of the composition shown in Table 3 are blended with lubricating base oil (Examples 6 to 8) and comparative lubricating oil compositions (Comparative Examples 9 to 10), A lubricating oil composition for reference (Reference Examples 1 to 2) was prepared. The following friction tests are conducted on these compositions, and the initial friction coefficient between the composite material mainly composed of fluororesin including graphite and the cylinder material, and the friction coefficient reach a certain level. The time until was evaluated.

As is apparent from the results in Table 3, the composition containing the (A) component and the (B) component of the present invention can set the initial friction coefficient high, and can maintain the friction coefficient stably. C) It can be stably maintained for a longer time by adding the component.

On the other hand, a composition containing no component (A) or (B), and a composition containing a fatty acid ester not satisfying the provisions of the component (B) of this application (Comparative Examples 9 to 10) In Reference Examples 1 and 2), the friction coefficient increases in a short time, and it is difficult to maintain the initial friction coefficient. table 1

* 110 ° C, constant overload

1) Refined mineral oil: 40 ° C Kinematic viscosity: 6.1 mmVs

2) 97% monoester, 0.1% diester, 0.1% triester, 3% other ingredients

3) Triester 97%, Diester 0.1%, Monoester 0.1%, Other components 3%

4) PMA, phenolic antioxidant, metal deactivator, defoamer

Table 2

* 1 10 ° C, constant overload

1) Refined mineral oil: 40 ° C kinematic viscosity: 6.1 mm ² / s

2) 97% monoester, 0.1% diester, 0.1% triester, 3% other ingredients

3) Triester 97%, Diester 0.1%, Monoester 0.1%, Other components 3%

4) PMA, phenolic antioxidant, metal deactivator, defoamer

Table 3

* 1 10 ° C, constant overload

1) Refined mineral oil: 40 ° C kinematic viscosity: 6.1 mm ² / s

2) Monoester 97% by mass, Diester 0.1% by mass, Triester 0.1% by mass, Other components 3% by mass

3) Monoester 78 mass%, diester 20 mass%, triester 0.1 mass%, other ingredients 2 mass%

4) Triester 97% by weight, diester 0.1% by weight, monoester 0.1% by weight, other components 3% by weight

5) Polybutyl succinic acid-polyamine reaction product, number average molecular weight of boribenyl group: 1300, nitrogen content: 1.8% by mass, boron content: 0% by mass, imino group / amino group ratio: 11.1

6) PMA, phenolic antioxidant, metal deactivator, defoamer

Claims

The scope of the claims

1. In the lubricating base oil, (A) at least one selected from phosphoric esters, phosphites and salts thereof having a hydrocarbon group with 3 to 30 carbon atoms, and (B) carbon number 6-30 saturated or unsaturated fatty acid glycerin ester, based on the total amount of the ester, the triester is 10% by mass or less, and the mass ratio of the monoester to the total monoester and diester is 0.5 or more. A hydraulic fluid composition for a shock absorber, comprising:

2. The component (A) is at least one selected from (A 1) phosphoric acid esters having 3 to 10 carbon atoms, phosphites and salts thereof. 2. The hydraulic fluid composition for a shock absorber according to item 1.

3. The component (A) has (A 2) a phosphorous ester having an alkyl group or alkenyl group having 11 to 30 carbon atoms, or an alkyl group or alkenyl group. 2. The hydraulic fluid composition for a shock absorber according to item 1, which is at least one selected from acid esteramine salts.

4. The hydraulic fluid composition for a shock absorber according to any one of Items 1 to 3, further comprising (C) a basic nitrogen-containing compound.

5. The component (C) comprises (C 1) an amine compound having 8 to 30 carbon atoms or an alkenyl group and derivatives thereof, and (C 2) an alkyl having 3 to 40 carbon atoms. 5. The hydraulic fluid composition for a shock absorber according to item 4, which is one or more selected from an amine compound having a group or an alkenyl group and derivatives thereof.

6. The mass ratio of the amount of nitrogen caused by the component (C) to the amount of phosphorus caused by the component (A) (NZP ratio) The force is 0.05 to 2, or the fourth item or The hydraulic fluid composition for a shock absorber according to Item 5.

7. The hydraulic fluid composition for a shock absorber according to any one of items 1 to 6, wherein the hydraulic fluid composition is for a shock absorber having a biston equipped with a fluororesin-based sliding material.